Security system



e United States Patent 1111 3,544,722

[72] Inventors Thomas C-Hlttfleld; 3,287,500 11/1966 Moore 179/5 Erich F. Feigl; Richard L. Davis, Los 3,092,819 6/1963 Cochinal 340/414 pp No cumin Primary ExaminerRalph D. Blakeslee I Filed Sept. 1967 Attorney-Ntlsson, Robbins, W1lls & Berliner [45] Patented Dec. 1, 1970 8 Computer Sammy Sysums ABSTRACT: The disclosed system is for summoning LoiAllleksaclmomh assistance and operates in conjunction with a conventional limited Partnership telephone station. The system includes a loop of magnetic recording medium divided into a plurality of parallel channels and a plurality of sequential sections. One of several sensor [54] units initiates operation of the system and additionally controls the system to selectively sense a particular recording [52] US. Cl. 179/5, 1 channel to summon a particular type of assistance.

340/412- In this regard, one channel may be employed for signals to [5]] Int. Cl. 4m 11/041 summon the fire department while signals recorded in another [50] Field ofSearch 179/5, channel serve to summon the police and so on. The system 5(P), l(VC), 90(BB); 340/412, 414 f also incorporates means for verifying the fact that the message 1 has been communicated. Specifically, means are provided for: 1 Remnm cued verifying the occurrence of a dial tone before supplying dial- UNITED STATES PATENTS ing signals; verifying communication with the desired station 2,416,445 2/1947 Jensen ..l79/90(BB)UX before Providing the message to Summon help; and verifying 2 827 515 3/1958 Zuber 179/5(p)UX. receipt of the message requesting assistance. Still further, this 3 2 031 1 19 Geddes 179/1 v i system incorporates structure for dialing secondary sources of 314271401 2/1969 Waddell 179/s 1 )ux help ifwmmunicamn is established with the P SECURITY YSTEM BACKGROUND AND SUMMARY OF THE INVENTION emergency situation; or the person aware of an emergency may find communication physically ormentally difficult or impossible. Therefore, substantial need exists for an automatic system capable of reliably acting to summon assistance in response to various emergencies. p

In general, various agencies or authorities serve to assist in various emergencies. For example, in the event of a fire, one may merely summon the fire department and expect assistance. Similarly, police departments are responsive to certain types of emergency conditions. However, in various other emergency situations, the person or organization capable of providing assistance may not be accustomed to receiving emergency calls. For example, a disabled refrigeration system-in a supermarket may present a rather grave emergency; however, standby assistance may or may not bereadily available. Therefore, a need exists for a systemto summon certain specific assistance, in response to any of a variety'of conditions manifesting an emergency, which system is capable of operating effectively with persons andorganizations that do not routinely receive emergency ealls;

Recent years have evidenced a continuing trend toward'increased crime. Statistically, burglary is one of the most prevalent forms of criminal activity. Of course, the burglar seeks to accomplish a theft without detection and ironically, the best interests of the victim are frequently parallel in this regard. That is, a burglar who is caught in the act of his crime may become violent, injuring or killing anyone interfering desirable to summon police assistance to a building that has been illegally entered, withno perceivable indications at the building. In other situations, it, may be desirable .to provide an audible alarm or signal at the building-site with the objective of informing the burglar of his detection in the hope that he will then depart from the premises. Therefore, itiis desirable to provide an alarm or security system which may be reliably operated with or without manifestations at the location to whichassistance is being summoned.

In the past, various alarms, security systems, and the like have been proposed. However, one of the difficulties involved.

with many such systems has been their unreliability. In this regard, the use of an unreliable system may be worse than usingno system at all. Therefore, considerable need exists for a system that is truly reliable to respond to the various stages of establishing a communication channel, and that onfailing, repeatedly attempts to establish communication and summon assistance until a request for assistance has been acknowledged.

, In general, the present invention is directed to an apparatus for monitoring or guarding a particularlocation as a home,

business establishment and so on. Specifically, the systemfunctions in cooperation with a conventional-telephone installation located on the guarded premises. The system utilizes the 2 pie, initially the system awaits a dial tone prior to providing dial pulses to the telephone installation. Similarly, the system awaits a human voice prior-to providing a vocal request for the detailed structure of an embodiment hereof; and

assistance. Furthermore, the system awaits an acknowledgement from the party with whom communication is established, prior to halting its operation. That is, the system repeatedly attempts to summon assistance, as from many persons or agencies, until an acknowledgement is provided indicating that assistance 'will be given.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, which constitute a part of this specification, an exemplary embodiment demonstrating various objectives and features hereof is set forth; specifically:

FIG. 1 is a'block diagram illustrative of the basic operation of a system incorporating the present invention;

FIG. 2 is a chart illustrating the format employed in the magnetic tape memory utilized in the system hereof;

FIG. 3, is a schematic and perspective diagram illustrating FIG. 4 is a diagrammatic representation of one component of the system of FIG. 3.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENT Referring initially to FIG. 1, there is shown an exemplary system hereof utilizing a plurality of sensors S which function tion, the sensors S comprise a wide variety of different transducers, sensors, switches, and so on. For example, first sensor may comprise a thermostat which provides an electrical signal when ambient temperature reaches a level indicative of fire. The second sensor may then comprise a series of switches physically mounted at windows, doors, or other places of entry, whichswitches provide a signal to indicate that an unauthorized person has violated the premises. Thus, the sensors '8 may comprise any devices for providing electrical signals indicative that help should be summoned. Also the sensors S may each indicatetheneed for a different type of help. As indicated, many sensors to and including the Nth sensor may be provided, each for detecting a particular'typ'e of emergency. Other examples, include: a thermostat placed in a cold storage facility to indicate failure of the refrigeration system, a small radio transmitter carried by a heart patient operable to indicate the occurrence of an attack, and so on.

- The signals from each'of the sensors S are connected to provide an electrical signal pulse to a control and memory system C which functions to summon the desired assistance through the telephone system T by contacting a person who may provide assistance, at one of the remote stations I-l (including stations 1 through N).

Considering a specific example, assume that the first sensor provides an electrical signal pulse to the system C, indicating that a fire has broken out on the premises of the installation. Thereupon, the system C seizes the local telephone station (incorporated in the telephone system T) and awaits a dial tone. If a-dial tone is not received, the system C releases the telephone station briefly, then again siezes the station or line. This operation is repeated until tone is received,' after which the system C delivers dialing signals to the telephone system T to establish communication with a selected one of the stations l-I, e.g. the first remote station which is the fire department.

After'dialing'operations are complete, the system C awaits the audible sound of a human voice answering the telephone at" the first remote station; If no voice is forthcoming, the system proceeds. to a secondary'operation-as described below. However, if the voice if forthcoming. the system provides the emergency message from recorded memory and requests that an acknowledgement be made. If the acknowledgement is received, the system returns to a quiescent state. However, again if an acknowledgement is not received the system proceeds to the secondary operation.

' pact physical unit.

V f As indicated above, any failure bythe system C to accomplish communication witharernote station results in-atsecondary pattern 'of operation. For example, communication 'rnay be temporarily suspended with certain remote stations (doctors office, refrigeration expert, and so'on) *lnsuch a case, the system proceeds during another cycle of operation to establish communication with'a secondary remote station e.g.

the Nth statiomAgain, the communicationis conditionedupon positive responses andthe failure thereof will-cause the system to proceed to a third operating cycle or return to the first operating cycle. In this regard, each installation will be" operated to accommodateparticular-needs; 1

which functions in cooperative'relationship'with one. of the Recapitulat'ing, the system. as generally presented in l lG, l

functions to sense any of'a variety of emergencies and attempt to summon the appropriate assistance viatelephone. Failing communication the systern proceeds to summon other assistance from secondary remote stations, repeating the cycle until an acknowled'gement'of the request for help is positively received Thus, the" system is reliable, direct, andas described 1 b belowmay be embodied ina relatively economical and com- Preliminary to considering the detailed structure of the exemplary embodiment, the chart of FIG. 2 will be considered which illustrates the format of thememory in the system C-" In this regard, the memory may comprise a loop of magnetic tape (illustratively employed herein) or various otherequivalent memorystructures. j I Electromagnetic transducer heads 11 (extreme left, FIG. 2)

sense a representative strip 12 of magnetic-recording medium by'horizontally scanning three distinct trackso'r channels 14,

magnetic sensing heads 32, 34 or 36. Asexplained above, the

head selected for operation depends upon the nature of the I assistance required. Furthermore the tape loop is also div-ided into sequential sections each of which carry the information to request assistance from a particular source,.the

. sources being arranged in their order of priority.

The selection of a particular one of the heads 32, 34 or 36, depends upon which of a plurality of sensors 38, 40 or 42 indicatesthe o'ccurrence of an emergencyAs described above,

the sensors-,maytakea wide variety of forms. as well known and widelyjpsedin.the. prior art; however, functionally, the sensors-operate to provide an electrical pulse on occurrence 1 ,of an emergencysituation. The pulses from thesensors 38, 40

respectively. These triggers may comprise anyof a variety of and 42 are electricallyco'upled to triggers 44, 46and 48 I ,well known bistable devices, e.g. multivibrators, which provide two binary signals, (in opposite states) depending upon the state of the device. Upon receiving a pulsev from an associated sensor, thetriggers 44,46 and 48 are set, to provide a high signal'to an associated andgate 50, 52 and 54.

The and? gates 50, 52 and; 54 may comprise any of a variety of well known multiple-inputlogic devices, which provide a high binary output'upon receiving unanimous high binary inputs. Functionally, the an 1 gates 50, 52 and 54 select one of the three channelson-the loop 30 in accordance with 16- and 18 considered defined thereon. lnaccordance with'the,

' operation of this system (as described below)one of the channels is selectively sensed depending upon 'whichof the sensors provides a signal indicating a need for assistance. For example, channel 14 may serve to summonffire fighting equipment,

. The formats in which information is'recorded each of the The second sfiction contains the recorded data" forirequesting assistance from a source of second priority. Of course, various numbersof sections may be recorded in accordance with the requirements of a particular installation and finally the ehan-.

nels all close. I

Considering the memory format in'greater detail, assumea channel 16 to summon the policearid channel 18 to summon a "medical doctor.

the conditioned outputs from the sensors 38, and 42. Also these gates establish the priority existing between the sensors.

*That is, for example,if the sensor 38 functions to sense a fire while the sensor 42 functions to sense aninoperative'refrigeration system the structure gives the sensor 38 priority overthe sensor 42.

I .Thepriority among the individual 38,40 and 42 is afforded by qualifying the and? gates 50,52 and 54 by the output signals from the triggers 44, 46 and 48. Specifically, the

sensor 38 :is given the highest priority and an output pulse therefromsets the trigger 44, fully qualifying the and gate 40 50 for the passage of signals from the head 36. The sensor 40 sets thetrigger 46 to qualify the and" gate 52 which also is affordedsecondary 'priority'and an output pulsetherefrom r equires qualification by'a-high signal in a conductor 60 indicatingthat'the trigger 44 is in a reset state or inactive.

- Somewhat similarly, the and gate54 requires qualification by the trigger 48 being set'(as applied to the gate through a conductor 62) as well as the occurrence of the trigger circuits 44 and 46 being reset (manifest by signalsin conductors 60 and 64).

controlled movement of the strip 12 in relation-tothe' heads 7 -l l, and further assume that the heads are selectively energized to sense onlythe channel 14 (or alternatively only the output from channel l4is accepted). When the system receives a dial tone, the tape'strip l2 movesfrom home position, designated by an arrow 20and dialing pulses aresensed from a segment 22. Thereafter,a signal indicating the completion of the dialing pulses is provided from a segment 24. The next segment 26 of channel 14 provides audio signals carrying the message requesting assistance, which is also terminated by acoriipletion signal contained in segment 28L p I he sequence of the segments 22,124, 26 and 28 is then repeated in the channel 11 of 'a section directed tothe second priority source of assistance. Of course, the number, of cycles to summon alternate source of assistance will vary widely, de-

pending upon individual installation requirements, as willibe readily apparent on understanding the total'system hereof as illustrated'in FIG.' 3. i

f a The format of the'channels l6 and 1 8 similar however, of V 7 course using different data. i

As explained above, the exemplary system herein employs a tape loop (FIG, 3 upper left) of magnetic recording-tape recorded with the format considered above. Thus, the tape is divided (in a parallel fashion) into three channels each of Recapitulating if any of the sensors 38, 40 or 42 detect an emergency condition, a signal is applied to qualify one of the and gates 50, 52 or 54 permitting the passage of signals fromia selected one of the heads 32, 34 or 36 depending .upon

thenature'of assistance required. Simultaneously with this operation, when one of the triggers 44, 46 or 48 is set, a signal (high-state binary) is applied through a junction 66, an and gate 67 (qualified by a home signal ll explained below and a pulse circuit 68 to the-energize" input of a tape drive unit 70.

'The puls'e circuit 68-may take a wide variety of different forms, comprising simply a structure to provide a pulse in response to a binary level change. The tape drive unit 70 may also take awide variety of different forms including means for frictional engagement with the tape loop 30 and a motivation device for displacing the tape loop 30 relative to the heads 32, 34 arid 36 to provide electrical signals as well known in the taperecording art. The tape drive unit is placed in on standby upon-receiving the pulse onits energize input, drives the tape on receiving a-signal at its go input and is turned off receiving a pulse at its stop" input.

The tape loop 30' is driven in alinement with the heads 32, 34 and 36 with the resultthat signals (amplified and processed as'w'ell known in the tape recording are selectively passed by one of the and" gates 50, 52 or 54 to a junction 72. it is to be noted, that the various junctions employed herein may comprise well known elements termed or" gates which funcsome forms of structural design may avoid the need for theseelements. n

Recapitulating, upon detection of an emergency situation, signals are supplied to the junction 72 which initially manifest dialing signals for a selected remote telephone station and then subsequently present signals representative of an oral request for assistance. Concurrently with these initial operations a signal is also applied from one of the triggers 44, 46 or 48 through the junction 66, the gate 67 and the pulse circuit 68 to a seize input of the telephone installation 74. This unit comprises a conventional telephone installation as in wide spread use to transmit data signals. The installation 74 has a seize input which upon receiving a signal, e.g. a pulse, seizes the outgoing telephone communication line thereby requesting a dial tone. The installation also includes a release" input, which upon receipt of a pulse releases the telephone line. Additionally, the installation 74 includes a di al line input for receiving dial pulses, a voice input for receiving audio signals for voice transmission, and an audio output for delivering audio signals receives from a remote sta tion through the telephone system.

vln general, the operation of the system hereof to supply con-. trolled and conditioned. signals to the telephone installation 74 from the tape loop 30 is accomplished by a control system generally indicated at 80 (lower right, FIG. 3). The system 80 includes a ring counter 82 having five active states and a single "home" position. Of course, the counter 82 may take various electronic and other forms; however, for illustrative purposes the counter 82 is represented byan electromechanical analosy- That is, a positively energized rotary contact 84 is indicated to be progressively stepped from a home" contact 86 to five sequentially arranged position contacts connected respectively to conductors 88 90, 92, 94 and 96. When the movable contact 84 is in the home position, signal H is high,

. otherwise one of the output conductors receives a high or positive signal level.

Continuing with the elcctromechanicalanalogy, the counter 82 includes an electromechanical stepper 100 connected to receive pulses from. a step" input 102 and a res et" input;

The reset signal R recycles the sequence of operation as will be explained in detail below. That is, in the event a dial tone is not received after a predetermined-delay interval of waiting, if

" the remote telephone is not answered within a period of waiting, or if a stated message is not acknowledged, the system provides a high level for the binary signal R, causing another sequence of operation pursuing an attempt to obtain assistance from the next source in the-priority list. H

Assuming thatin. the routine operation of the telephone installation 74 and the equipment associated therewith, seizing the telephone line results ina dial tone at the audio output that tone passes through a dial tone filter and rectifier circuit 116 providing a positive signal through a conductor 118 to an "and", gate 120. The and 120(during this interval) is also qualified by a signal applied through the conductor 88 (energized while the counter 82 is in the first stage). Therefore, the and gate .120 applies a signal through the junction 110 and the input 102 to advance the counter.,82 to the .second stage of operation.

During the second stage of operation, the output conductor 90 from the counter 82 receives a positive signal which is applied through a junction.12l to drive the tape drive unit .70. That is, prior to this time, the tape drive unit has beenenergized in a standby state; however, it is now commanded to GO" and produces relative motion between the tape loop and the currently active head-32. Thereupon, the signals representative of dialing pulses are provided from the head 32 through the "and" gate 54,'the conductor 124 the and gate 126and a'conductor 128 to the dial line input of the telephone installation 74. It is to be noted that during this interval the and gate 126 is qualified by the signal in the conductor 90, which signal is high during the interval of the second stage of operation. Thus, dialing signals'are supplied from the tape loop 30 to the dial line input of the telephone installation 74' causing a predeterminedstation designation to be automati cally dialedl'f On completion of the dialing signals from the tape loop 30,

the head 32 senses acornrnand signal indicating the completion of the dialing sequence. The commandsignalinthe present exemplary system is a 5 ,000-cycle signal, hich on 104. Each time a pulse is received on the step" input 102; the j stepper 100 sequentially advances the contact 84to'the next thereof may now best be obtained by assuming certain initial conditions and explaining the following operating sequence concurrently with the introduction of further component parts of this system. Therefore, assume that the sensor 42is actuated by detecting an emergency condition to provide an electric al pulse which sets the trigger 48. Assume further, that both the triggers 44 and 46 are reset, so that all inputs to the "and" gate 54 are'high (in each of the conductors 62 64 and 60) thereby enabling the gate 54 to pass signals from .the third channel via the head 32 to the junction 72. 7

Somewhat simultaneously to the above-described operations, the setting of the trigger 48 results in the application of a pulse from the pulse circuit 68 to the seize input of the telephone installation 74 thereby seizing the telephone line- The pulse from the circuit 68 is also applied-tothe energize passage through the and gate 1:26is applied through a 5,000

- cycle band-pass filter and rectificr-130 which develops a signal level that is applied through the junction 1 10 to the step input 102 and thereby advances the counter 82 to the third stage of operation by stepping the movable contact 84 to provide a high output on the conductor 92.

The third stage of operation is another waiting interval during which the system stands by for an indication that communication has been established. This manifestation is the occur rence of a human voice from the audio output of the telephone installation 74. That is, the system now stands by for ajpredetermined interval waitingfor the remote telephone to be answered. During the waiting interval, only the conductor 92 from the counter unit 82 carries a high signal therefore the delay circuit 112.is again energized; however, the tape drive unit is'not in a G0 state. As previously explained, unless 'the telephone at the remote state is answered within a predetermined period, the delay circuit 112 provides the abortive signal R in a high state causing the system to reset and make another complete attempt at establishing communica tion. 7 a

If the telephone is answered, voice range frequency signals are received from the audio output of the telephone installation 74. Such signals pass through a selective voice range step input of the counter 82, thereby advancing the contact 84 from the home" position 86 to provide a'positive signal to the output conductor 88. I

The conductor 88 (along with several other conductors) is connected througha junction 89 to a delay apparatus 112 which may comprise a delay relay that develops a signal R, at a predetermined, interval after-receiving a positive input signal.

band-pass filter and rectifier circuit 132 which provides a high output man and gate 134 indicating a human voice is car-' ried on the audio output from the-telephone installation 74.

The gate gate 134 is qualified during this interval by a signal' carried by the conductor 92 which is connected to receive the output from the counter '82. Therefore, the ;and" gate 134 applies a stepping signal through the junction to the step input 102 advancing the counter 82 to the fourth stage of operation.

counter 144 upon receiving a series of pulses telephone installation,

stage of operation, the out- Rprovided from the delay ciicuit 112. The reset signal is apput from the counter 82 to the conductor 92 is high thereby.

driving the tape unit 70 to *GO through'the junction 121.. Therefore, the tape30' is moved in relation to the sensing head 32 with the result that prerecorded signalsrep'resentative .of the voice message are fsensedby thehead 3 2 and applied through the and gate 54 and a gate 136 to the voice input of l the telephone installation 74. The.and" gate 136 is con-.

nected directly to the conductor 94 which, as indicated above,

provides a high signal duringthe fourth stage of operation, 5

M the conclusion of-thei vocalfmessage another control signal is sensed from the tape loop 30 in the form of a-5,000- 3 cycle signal which is again appliedto thefilterand rectifier circuit 130forthe development of a positive 'signal which is i applied through the junction 110 to .the step input 102 of the the acknowledgement of the request for help. x

The output from the counter isfagain applied to thedelay circuit 112 (through conductor 96) to commandfarecycle operation if no'acknowledgement is received. Specifically, for

example, .the' prerecorded vocal request-for help; either requests an acknowledgement or the stationfrom' which help has been summoned routinely provides an acknowledgement in response to calls'originating from:-the structural system 82 thereby advancing the counter to the fifth stage of 0 operation. During this stage-of operation, the system awaits plied directly to the release input of the telephone installation 74 to release the telephone line. That is, the application of the reset signal R to the'telephone installation 74. releases the line which was previouslyseized;

Additionally, the reset signal R'is applied through the junction 110 to thestep input 102 of the counter 82. As a result, the counter. 82 is advanced to the next stage of operation, e.g. stage two, four or homeif the stageof operation is stage two or four, the system proceeds in synchronism with the revolution of the tape loop 30 until the first priority source information on the tape has passed the heads. Coincidental to suchabortive action, the counter 82 is returned to the home position at which "the signal H is provided high to again qualify the and gate 67. It is to be recalledthat the gate 67 also receivesan input from the trigger circuit 48 registering the fact that an unreported emergency still exists. Upon qualification of the gate v6'I,a pulse is supplied from the circuit 68 to-seizea line in the telephone system "and advance the counter .unit 82 to the' first stage'of operation of the system.

Subsequently, the cycle of events is precisely as described above however, in this instance the'system is attempting communication with a source of assistance designated as .second priority", as recorded on the tape loop substantially as indicated on the chart of FIG. 2;

. In various applications, .the second priority source .of

; assistance may include a more remote fire station, a more hereof. The exemplary form ,of acknowledgementcomprises theremote stationdialing'a-prearrangedsingle digit on the v telephone instrument at that station- The system hereof then 1 functions to detect such an, occurrence to provide a [clear signal D which returns the systemic a standby status awaiting another possible emergency. 3 r

When a preselected number is dialed atthe'remote'station;

a coinciding number of dialing signals appear at the audio out-,

put from the telephone installation 74. Those pulses are.a pplied through ari=and-" gate 1 40 (lower right, FIG. 3) which is. occurin'ginthe conductorflfi duringthe fifth stage of operationrfljhe: dial sequencesensor niay take ai qualified by'a signal counts the dialing pulsesfor'v'erificationfofa.prearranged remote police precinct, a property owner or virtually any.

othersecond'priority source, ofhelp. Of course, as indicated above,third-priorityzsources 10f assistance may also be summcnedin accordance with the present system as will be readi 1 lyapparent to those skilled in the from this explanation.

, As indicated, the dial sequence sensor unit 142 (FIG; 3)

may take a .wide variety of different forms, one rather simple form of which is shown in FIG. 4, Specifically, input is provided to a terminal 160 which is connected to a delaycircuit 162 and to one inputof amonostable multivibrator 164 and to a similar input ofeach of a remaining number of monostable i variety of different forms including abinary counter .which" a "number. One form of "suchia circuitis disclosedin FIG. 4 and 1 will be considered hereinafterhowever, at the present stage of 1 explanation, it is to be understood tha't functionally, the dial sequence sensor through a conductor 30 is in a home "homeiposition. Thereupon, the gateldo is qualified to provide a deene'rgized. signal D. The signal D is applied to the tape drive'unit70 deenergizing thatunit) to each of the'trig'gers 44, 46 and 48 (resetting the trigger 48) to the resetf input ofthe counter 82'(re'setting that unit) and to a clear input of thesensor'lfl (clearing that unit). Thus, the.

' system is returned to a 'q'uiescel State during-which it again.

awaits the occurrence of the manifestation of an emergency 1 from one of the sensors 38, 40 or 42.

Thrcughoutthe above explanation, it was assumedthat the z operation of the system caused a responsive dial tone from the 142 provides a highoutput to a conductor coinciding to a predeterknown to have beenacknowle'dged andthe system may halt 30 returns its quiescent position. In this regard,-th e 30 carries a metallic contact ,148 which cooperates" 'with a pair of contacts to provide an electrical signal f 15230 the gate 146 when the tape loop 1 rnultivibra'tors 166 and so on, through and"gates 170 and so .omThe chain" is terminated byaflip-flop 168 which is'connected to" the inputiterminal through a gate fl 7 2,.and

similarly to the unstable. sid e of .themultivibrator 166. Thus,

the inultivibrator's and the flip-flops comprise a binary counter "as well known in the prior art interconnected by and gates which must be qualifiedfto accomplish the sequential setting of the multivibrators; In this regard, 'multivibrators are-very well known which possess only one stable state. Upon. being pulsed to their unstable state, they impose a brief delayv then returnto the stable state. These periods of delay are'applied to verify the-periods between dialing pulses in the acknowledgement signal. That is, each dialing pulse must be followed by another in time, or the multivibra tor that was set by the former pulseresets and the chain sequence is broken. Of course, the last pulse in the chain sets the bistable flip-flop 168 prior to *itheidelay period imposed by the delay period imposed by-the 'delay circuit 1 62 and an acknowledgement is indicated.

in the sequential operation of this apparatus the application of a series of pulses manifesting the, dialing operation at the remoteltelephone instrument actuates the delay circuit 162 and similarly initiates stepping operations by the multivibra tors 164, 166 and so on. The-delay circuit 162 affords a sufficient period for all of the multivibrators and-the flip-flops in that theremote station telephone was answered by .a human voice,'and that the -.re questfor assistance wasacknowledged; As indicated, at various junctures throughout the i above explanation, failure of such responsive sequences results inthe production of a reset signal .the chain to be set before providing a reset output to a con ductor172. Of course, each of the multivibrators and the flipflop are provided to operate on the leading edge of the pulses so that one maybe set during each pulse, as very well known in the computer and data-processing art. Therefore, if a" sequence of dialing pulses'is truly provided at the input 160,

the flip-flop 168 is set prior to the tirne whenthe signal.

emerges from thedelay circuit 162. driving the conductor 172 high and resetting the entire chain except the flip-flop 168.

However, conversely, if the multivibrators should be perchance randomly set by noiseor other signals their auto- I 9 matic reset and the delay circuit 162 will clear them before the last flip-flop 168 in the chain is set. 7

Upon setting the flip-flop 168, an output signal is provides from the sequence sensor, which signal endures until a reset may be accomplished; therefore, the system hereof shall not be limited in scope to the illustrative embodiment, but rather shall be determined in accordance with interpretations of the claims set forth below.

We claim:

1. A security system for operation with a telephone statio to summon assistance or manifest emergency messages at a remote location through a telephone system, comprising:

a plurality of electrical sensor units, each to provide a sensor signal in response to conditions indicating a need for assistance at the location of said telephone station;

means for providing dialing signals for a plurality of telephone designations;

means for registering a plurality of different message signals representative of a plurality of different emergency messages, said different message signals having a.

A 10 sor units, said means for'providing dialing signals and said means for registering said control means for receiving said sensor signals to thereupon actuate said means for providing dialing signals and message signals to said 7 telephone system in accordance with said predetermined order of priority.

2. A system according to claim 1 further including means for sensing the occurrence of voice tones from said telephone station to provide an electrical voice signal and wherein said control means includes means to control said means for providing said message signals'under control of said voice signal.

3. A system according to claim 2 wherein said control means includes means for repeating operations of said means for providing dialing signals and said means for registering a 'pluralityof different message signals under control of said a voice signal;

acknowledgement of summoned assistance, whereby to halt an operating cycle of said-system,- 

